1. Field of the Invention
The present invention relates to machine tools, and more particularly, to apparatus for hydraulically pivoting a rotating cutting tool.
2. Description of the Prior Art
Various machine tools can be found in the prior art for laterally positioning a rotating cutting element. One of the earliest devices included a gear operated sliding assembly. The rate of lateral movement of the sliding assembly was a function of the gear ratio. The gear ratio was generally not variable without dismantling the machine tool. The resultant lost time during gear changes wasted valuable machinists' time and increased the cost of the product being fabricated. In addition, machinists would at times use improper gear ratios in an effort to expedite the machining process. Such action tended to produce less than optimum quality work.
To overcome the lack of variability in gear drive mechanisms, electro-mechanical devices were developed. These devices are generally satisfactory in performance but generate other problems. They need external electrical power sources and appropriate electrical switching gear to transmit electrical power from the source to the rotating machine tool. Furthermore, the continual presence of metallic shavings and cutting oil presented a hazard as they might short circuit the electrical components.
Several hydraulically operated laterally displaceable machine tools have also been developed. U.S. Pat. No. 3,422,705 illustrates a machine tool for cutting internal annular recesses using an ancillary hydraulic pressure source to actuate a piston. Movement of the piston is translated through a link to effect lateral movement of a rotating cutting element. U.S. Pat. No. 3,526,159 teaches a hydraulically operated machine tool for laterally displacing a rotating cutting element. An external source provides hydraulic fluid under pressure to axially displace a piston. Lateral movement of the piston is translated through gears to rotate a threaded shaft. Rotation of the shaft causes longitudinal displacement of the shaft which acts upon an inclined plane to laterally displace the cutting element.
Both of the above described hydraulic tools cannot be easily used on any existing jig bores or milling machines as each requires an external source of pressurized hydraulic fluid. In addition, the requirement for shafts and pistons aligned with the axis of rotation of the tool necessarily limits their minimum length. Thus, for any given jib bores or milling machines the size of the work piece is severly limited.
It is therefore a primary object of the present invention to provide a self contained machine tool ensemble attached to the collet of a rigid spindle machine and having a laterally displaceable cutting tool, which tool is displaced by a hydraulic force generated within the ensemble.
Another object of the present invention is to provide a compact machine tool ensemble attached to the collet of a rigid spindle machine and having a laterally displaceable cutting tool, which tool is displaced by a hydraulic force generated within the ensemble.
Yet another object of the present invention is to provide a rigid spindle machine supported machine tool ensemble which generates an infinitely variable hydraulic force to effect an infinitely variable lateral movement of an attached cutting tool.
Still another object of the present invention is to provide a machine tool ensemble attached to the collet of a rigid spindle machine and having manually operated means for controlling the surface finish effected by an attached cutting tool.
A further object of the present invention is to provide a cutting tool having a selectively variable rate of lateral movement, which cutting tool is laterally positioned by the hydraulic force generated by a supporting rotating machine tool.
A yet further object of the present invention is to provide a cutting tool supported by a machine tool having a vertically displaceable non-rotating annular member to reciprocate a pair of diametrically opposed hydraulic fluid pumps, which pumps generate a hydraulic force for effecting lateral displacement of the cutting tool.
A still further object of the present invention is to provide a quick return to the start position of a hydraulically positioned laterally displaceable cutting tool in a machine tool.
It is also an object of the present invention to provide a hydraulically operated machine tool having a hydraulic fluid pressure takeoff to operate a hydraulic mechanism for varying the angular orientation of a cutting tool.
It is also another object of the present invention to provide hydraulically operated attachments useable in conjunction with a hydraulic fluid pressure takeoff in a machine tool having a self contained and self generated hydraulic fluid pressure source.
These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.